The present invention relates to a dishwasher, in particular a household dishwasher, having a wash tub for receiving dishes during a wash program, having a dish detection device for detecting the dishes put into the wash tub, and a control device for controlling the sequence of the wash program depending on the detected dishes.
Current household dishwashers include a plurality of components, such as for instance pumps, heating devices, valves, water switches and dosing devices for detergents and cleaning aids, which interact to enable the cleaning of dishes put into the wash tub. To ensure this interaction, dishwashers comprise an electric or an electronic control device, which automatically controls the components of the dishwasher according to a wash program designed in advance. The design of the wash program has in this way a decisive influence on the efficiency of the dishwasher, which results from an offsetting on the one hand of the achieved cleaning and drying effect and on the other hand of the required usage of energy, water and detergents and cleaning aids.
Conventional control devices are embodied here such that the sequence of a wash program is fixedly predetermined. This means that the wash program, once it has been started by an operator, always proceeds in the same way. In order now to allow for the situation whereby in practice the dishwasher can be loaded differently from wash cycle to wash cycle, it has been usual for a long time to store different wash programs in the control device. A short program can therefore be provided for instance for only lightly soiled dishes, a normal program for normally soiled dishes and an intensive program for heavily soiled dishes. Here the selection of the suitable program is left to the operator. However, after one of the available wash programs is selected, the wash cycle is implemented according to the pattern which is predetermined by the selected wash program.
In contrast it has more recently been suggested that dishwashers should be provided with a dish detection device and the control device should be embodied such that the sequence of the selected wash program is automatically adjusted to the dishes detected by the dish detection device.
Known dish detection devices can be divided into two groups. A first group enables an estimation of the total quantity of dishes put into the wash tub. To this end sensors are used which may operate according to different physical principles. For instance it is known to provide sensors for determining the weight of the dishes directly in or on the wash tub in order to detect the total quantity of dishes.
A second known group of dish detection devices is provided to determine the type of dish elements to be washed. It has been proposed for instance to detect the contours of the dish elements by means of a light barrier when loading the dishwasher to distinguish plates from pots for instance.
The adjustment of the sequence of a wash program to the total quantity of dishes put into the wash tub and/or to the type of dish elements put in at best enables a gradual improvement in the efficiency of the dishwasher by comparison with older dishwashers. However the water and energy consumption and the detergent and cleaning aid usage, which is needed for an at least satisfactory cleaning of the item being washed, are far higher than currently required values.